"MIT’s old Building 20 was ugly and slapdash and meant to just last through World War II—which is why it was made out of wood even though that broke the fire code. Yet it stayed up until 1998 because it became an ideas factory. Radar was perfected there. The science of modern linguistics took shape there under Noam Chomsky. It housed labs in nuclear science, cosmic rays, and food technology. Control terminals used by the Tech Model Railroad Club became the computers on which early hackers tinkered in the early 1960s. What was the secret of Building 20?"